Lazy Day Oatmeal Cake

I've had this recipe for at least 30 years and have no idea where it came from but I can tell you it is easy easy to make. Always turns out great and is a bit hit at pot lucks.

Lazy Day Oatmeal Cake

1 cup rolled oats (NOT quick cooking oats)
1 1/4 cups water
1/2 cup butter
1 cup brown sugar
1 cup sugar
2 whole eggs
1 1/2 cups flour
1/2 tsp salt
1 tsp cinnamon
1/2 tsp allspice
1/2 tsp nutmeg
1 tsp baking soda

TOPPING:
6 Tbs butter
2 Tbs milk
3/4 cup brown sugar
1 cup shredded coconut meat
1 cup chopped walnuts

Bring water to a boil and add oats. Let stand for 20 minutes. Meanwhile cream eggs, butter and sugar. Sift together the dry ingredients and add to the creamed mixtures. Stir in the oats. Bake in a greased sheet cake pan at 350 for 35 minutes. Let the cake cool just a bit before putting on the topping.

Topping: Mix the 6 tbsp butter and 2 tbsp milk in a sauce pan. Heat until warm. Add the brown sugar and heat until boiling, stirring constantly. Add the chopped nuts and coconut. Spread on the still warm cake.